Add first-class logical UUID type support

[xiangfu0]

Summary

• add a first-class logical UUID type to Pinot v1, backed by the existing fixed-width 16-byte BYTES representation
• support UUID semantics across schema, ingest, planner/type resolution, casts, filters, grouping, distinct, ordering, joins, dictionaries, bloom filters, raw inverted indexes, and result rendering
• keep v1 backward-compatible at the storage and wire level: no segment format bump and no data-table format bump
• add unit coverage plus offline and realtime integration coverage extending CustomDataQueryClusterIntegrationTest
• document usage, limitations, and migration constraints in the README

Why

Today Pinot users typically model UUIDs as either STRING or BYTES.

That works for storage, but it loses type semantics:

• BYTES results render as hex instead of UUID text
• schema and query planning cannot distinguish UUIDs from arbitrary bytes
• ingest and query paths do not validate UUID values consistently
• joins, grouping, and distinct work physically, but not as a native logical type

This PR adds a native logical UUID type while intentionally reusing Pinot's current BYTES storage and wire encodings in v1.

V1 design contract

Aspect	Behavior
Logical type	UUID
Stored type	BYTES
Internal width	fixed 16 bytes
External text form	canonical lowercase RFC 4122 (8-4-4-4-12)
Result rendering	canonical UUID string for UUID columns
Plain BYTES behavior	unchanged, still rendered as hex
Multi-value support	not supported in v1
Segment/data-table format	unchanged in v1

User guide

1. Schema definition

Single-value UUID columns can be declared directly in the Pinot schema.

{
  "schemaName": "events",
  "dimensionFieldSpecs": [
    {
      "name": "eventId",
      "dataType": "UUID"
    },
    {
      "name": "traceId",
      "dataType": "UUID"
    }
  ],
  "dateTimeFieldSpecs": [
    {
      "name": "ts",
      "dataType": "LONG",
      "format": "1:MILLISECONDS:EPOCH",
      "granularity": "1:MILLISECONDS"
    }
  ]
}

If a schema declares a multi-value UUID column, validation now fails clearly.

2. Table behavior

UUID columns work with the same table features as other single-value dimension columns in v1, including:

• dictionary and no-dictionary columns
• bloom filters
• raw-value inverted indexes for no-dictionary UUID columns
• offline and realtime tables
• upsert primary-key use cases backed by UUID columns

Example table config fragment:

{
  "tableName": "events",
  "tableType": "REALTIME",
  "segmentsConfig": {
    "timeColumnName": "ts",
    "schemaName": "events"
  },
  "fieldConfigList": [
    {
      "name": "eventId",
      "encodingType": "RAW",
      "indexes": {
        "bloom": {},
        "inverted": {}
      }
    }
  ]
}

3. Ingest behavior

Pinot normalizes UUID inputs to a 16-byte internal representation.

Accepted v1 inputs:

• canonical lowercase UUID strings, for example 550e8400-e29b-41d4-a716-446655440000
• java.util.UUID
• 16-byte byte[]

Supported ingest paths covered in this PR:

• record-reader and segment-local normalization
• offline ingest
• realtime ingest
• Avro interop, including Avro logicalType: "uuid"

Invalid UUID values fail with explicit validation/conversion errors instead of silently degrading.

4. Query examples

Selection

SELECT eventId, traceId
FROM events
ORDER BY eventId
LIMIT 10

UUID columns are returned as canonical UUID strings.

CAST to UUID

SELECT eventId
FROM events
WHERE eventId = CAST('550e8400-e29b-41d4-a716-446655440000' AS UUID)

IN predicate

SELECT eventId
FROM events
WHERE eventId IN (
  CAST('550e8400-e29b-41d4-a716-446655440000' AS UUID),
  CAST('550e8400-e29b-41d4-a716-446655440001' AS UUID)
)

GROUP BY

SELECT eventId, COUNT(*)
FROM events
GROUP BY eventId
ORDER BY eventId

DISTINCT

SELECT DISTINCT eventId
FROM events
ORDER BY eventId

ORDER BY

SELECT eventId, ts
FROM events
ORDER BY eventId, ts

Equality join

SELECT a.eventId, a.ts, b.ts
FROM events_offline a
JOIN events_realtime b
  ON a.eventId = b.eventId
WHERE a.eventId = CAST('550e8400-e29b-41d4-a716-446655440000' AS UUID)

These query patterns are covered for both SSE and MSE where applicable.

5. Result behavior

For columns declared as UUID:

• SELECT uuidCol FROM t returns canonical lowercase UUID strings
• GROUP BY, DISTINCT, and join outputs also render UUID strings
• Arrow and JSON broker response encoders both preserve UUID string rendering

For columns declared as BYTES:

• behavior stays unchanged
• results still render as hex
• no existing BYTES semantics are changed by this PR

6. Existing UUID byte/string helpers

This PR keeps the existing helper functions usable:

• toUUIDBytes(...)
• fromUUIDBytes(...)

The new logical UUID type is additive and does not replace plain BYTES workflows.

Migration notes

Schema evolution constraint

Pinot does not support changing the data type of an existing column in place. This PR adds a new logical type, but it does not change that schema-evolution rule.

From STRING

If a column currently stores canonical UUID strings and should behave as a typed UUID column, the practical path is to create a new UUID column or a new table/schema and reingest or backfill the data.

From BYTES

If a column already stores 16-byte UUID payloads, declaring a new column as UUID gives UUID-aware query behavior and rendering, but existing BYTES columns remain BYTES columns. Adopting the logical UUID type still requires a new column or table rebuild/reingest rather than an in-place type mutation.

Important distinction

A column must be declared as UUID to get UUID result rendering. Declaring the column as BYTES continues to render hex, even if the underlying bytes happen to represent UUID values.

Format compatibility

The UUID type itself does not require a segment or data-table wire format bump in v1. That compatibility statement is about representation, not about in-place schema migration.

Scope exclusions in v1

This PR intentionally does not include:

• multi-value UUID columns
• segment format changes
• data-table wire format changes
• in-place schema type mutation from existing STRING or BYTES columns to UUID
• a broader reinterpretation of plain BYTES columns as UUIDs
• UUID range predicate support as part of the v1 contract

Validation

Targeted local validation run for this branch includes:

• ./mvnw -pl pinot-spi -Dtest=FieldSpecTest,SchemaTest test -Dcheckstyle.skip=true
• ./mvnw -pl pinot-common,pinot-core -am -Dtest=JsonResponseEncoderTest,ArrowResponseEncoderTest,BytesDistinctTableTest,SelectionOperatorUtilsTest,CastTransformFunctionTest,ScalarTransformFunctionWrapperTest -Dsurefire.failIfNoSpecifiedTests=false -Dcheckstyle.skip=true test
• ./mvnw -pl pinot-segment-local,pinot-segment-spi -am -Dtest=MutableDictionaryTest,DefaultNullValueVirtualColumnProviderTest,RawValueBitmapInvertedIndexTest,BloomFilterCreatorTest,BloomFilterSegmentPrunerTest -Dsurefire.failIfNoSpecifiedTests=false -Dcheckstyle.skip=true test
• ./mvnw -pl pinot-plugins/pinot-input-format/pinot-avro-base -am -Dtest=AvroUtilsTest,AvroSchemaUtilTest -Dsurefire.failIfNoSpecifiedTests=false -Dcheckstyle.skip=true test
• ./mvnw -pl pinot-integration-tests -am -Dtest=UuidTypeTest,UuidTypeRealtimeTest -Dsurefire.failIfNoSpecifiedTests=false -Dcheckstyle.skip=true test
• ./mvnw -pl pinot-integration-tests -am -Ppinot-fastdev -Dtest=UuidTypeTest,UuidTypeRealtimeTest -Dsurefire.failIfNoSpecifiedTests=false -Dcheckstyle.skip=true test
• ./mvnw -pl pinot-common checkstyle:check license:check -DskipTests

GitHub Actions on this PR continue to run the full Pinot CI matrix.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 58.81579% with 313 lines in your changes missing coverage. Please review.
✅ Project coverage is 63.17%. Comparing base (34d3fd6) to head (c9ac093).

Files with missing lines	Patch %	Lines
...r/impl/inv/RawValueBitmapInvertedIndexCreator.java	56.48%	53 Missing and 4 partials ⚠️
...ot/common/request/context/RequestContextUtils.java	59.04%	33 Missing and 10 partials ⚠️
...ain/java/org/apache/pinot/spi/utils/UuidUtils.java	72.28%	13 Missing and 10 partials ⚠️
...a/org/apache/pinot/common/utils/PinotDataType.java	39.13%	14 Missing ⚠️
...main/java/org/apache/pinot/spi/data/FieldSpec.java	73.33%	8 Missing and 4 partials ⚠️
...mon/function/scalar/uuid/IsUuidScalarFunction.java	52.17%	11 Missing ⚠️
...mon/function/scalar/uuid/ToUuidScalarFunction.java	52.17%	11 Missing ⚠️
...inot/query/planner/logical/RexExpressionUtils.java	0.00%	11 Missing ⚠️
...ransform/function/IdentifierTransformFunction.java	0.00%	9 Missing and 1 partial ⚠️
...java/org/apache/pinot/common/utils/DataSchema.java	50.00%	6 Missing and 3 partials ⚠️
... and 28 more

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #18140      +/-   ##
============================================
+ Coverage     63.13%   63.17%   +0.03%     
- Complexity     1610     1616       +6     
============================================
  Files          3213     3222       +9     
  Lines        195730   196333     +603     
  Branches      30240    30338      +98     
============================================
+ Hits         123583   124041     +458     
- Misses        62281    62354      +73     
- Partials       9866     9938      +72     

Flag	Coverage Δ
integration	100.00% <ø> (+100.00%)	⬆️
integration1	100.00% <ø> (?)
integration2	0.00% <ø> (ø)
java-11	63.14% <58.81%> (+0.03%)	⬆️
java-21	63.10% <58.81%> (+<0.01%)	⬆️
temurin	63.17% <58.81%> (+0.03%)	⬆️
unittests	63.17% <58.81%> (+0.03%)	⬆️
unittests1	55.33% <43.15%> (-0.04%)	⬇️
unittests2	34.80% <29.60%> (+0.03%)	⬆️

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[Copilot]

Pull request overview

Adds a first-class logical UUID type to Pinot (backed by 16-byte BYTES in v1), and wires UUID semantics through schema/type handling, indexing, query planning/execution, and result formatting, with unit + integration coverage and user-facing documentation.

Changes:

• Introduce UUID as a logical type (FieldSpec.DataType.UUID / DataSchema.ColumnDataType.UUID) with canonical RFC 4122 lowercase string rendering via UuidUtils.
• Propagate UUID-aware behavior through dictionaries, bloom filters, raw-value inverted indexes, casts/literals, predicates, distinct/grouping, and query planner/runtime type mapping + (de)serialization.
• Add targeted unit tests plus offline/realtime integration tests and README documentation.

Reviewed changes

Copilot reviewed 76 out of 76 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
README.md	Document UUID logical type usage, casting, and migration notes.
pinot-spi/src/test/java/org/apache/pinot/spi/data/SchemaTest.java	Add schema validation tests for UUID SV-only and default handling.
pinot-spi/src/test/java/org/apache/pinot/spi/data/FieldSpecTest.java	Add UUID DataType storedType/size and conversion/default-null tests.
pinot-spi/src/main/java/org/apache/pinot/spi/utils/UuidUtils.java	New UUID conversion utilities (string/UUID/bytes/ByteArray).
pinot-spi/src/main/java/org/apache/pinot/spi/utils/CommonConstants.java	Add UUID null placeholders.
pinot-spi/src/main/java/org/apache/pinot/spi/data/Schema.java	Allow UUID in schema validation; enforce UUID SV-only.
pinot-spi/src/main/java/org/apache/pinot/spi/data/FieldSpec.java	Add UUID DataType and UUID-aware conversions/formatting/default handling.
pinot-segment-spi/src/main/java/org/apache/pinot/segment/spi/index/creator/BloomFilterCreator.java	Add UUID string rendering when inserting into bloom filters.
pinot-segment-local/src/test/java/org/apache/pinot/segment/local/segment/index/creator/inv/RawValueBitmapInvertedIndexTest.java	Extend raw inverted index tests to UUID + generic API path.
pinot-segment-local/src/test/java/org/apache/pinot/segment/local/segment/index/creator/BloomFilterCreatorTest.java	Add bloom filter creator test for UUID values stored as bytes.
pinot-segment-local/src/test/java/org/apache/pinot/segment/local/segment/index/column/DefaultNullValueVirtualColumnProviderTest.java	Add UUID coverage for virtual column default-null dictionary/metadata.
pinot-segment-local/src/test/java/org/apache/pinot/segment/local/realtime/impl/dictionary/MutableDictionaryTest.java	Add UUID canonical string lookup tests for mutable bytes dictionaries.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/readers/RawValueBitmapInvertedIndexReader.java	Make bytes dictionary logical-type aware; add getDocIdsForBytes.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/readers/OnHeapBytesDictionary.java	Add logical type to parse/format BYTES vs UUID.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/readers/ConstantValueBytesDictionary.java	Add logical type to parse/format BYTES vs UUID.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/readers/BytesDictionary.java	Add logical type to parse/format BYTES vs UUID.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/loader/invertedindex/InvertedIndexHandler.java	Use stored type; enable raw inverted index creation for UUID (stored as BYTES).
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/loader/columnminmaxvalue/ColumnMinMaxValueGenerator.java	Pass logical type into bytes dictionary for min/max generation.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/loader/bloomfilter/BloomFilterHandler.java	Use DataType-aware string formatting for bloom filter population (UUID vs BYTES).
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/dictionary/DictionaryIndexType.java	Plumb logical type into bytes dictionary and mutable dictionary creation.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/column/DefaultNullValueVirtualColumnProvider.java	Build bytes dictionary with logical type to format UUID defaults correctly.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/creator/impl/inv/RawValueBitmapInvertedIndexCreator.java	Fix raw inverted index dictionary temp-file handling; use ByteArray keys for BYTES/UUID.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/creator/impl/BaseSegmentCreator.java	Allow inverted index without dictionary for UUID via raw-value inverted index creator.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/realtime/impl/dictionary/MutableDictionaryFactory.java	Create bytes dictionaries with logical type (UUID vs BYTES) based on stored type.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/realtime/impl/dictionary/BytesOnHeapMutableDictionary.java	Add logical type parsing/formatting for UUID vs BYTES.
pinot-segment-local/src/main/java/org/apache/pinot/segment/local/realtime/impl/dictionary/BytesOffHeapMutableDictionary.java	Add logical type parsing/formatting for UUID vs BYTES.
pinot-query-runtime/src/main/java/org/apache/pinot/query/runtime/plan/server/ServerPlanRequestUtils.java	Emit UUID IN operands as canonical strings instead of raw bytes literals.
pinot-query-planner/src/test/java/org/apache/pinot/query/type/TypeFactoryTest.java	Add UUID type conversion tests and skip UUID array tests.
pinot-query-planner/src/test/java/org/apache/pinot/query/planner/serde/RexExpressionSerDeTest.java	Add UUID literal SerDe test and supported type list.
pinot-query-planner/src/test/java/org/apache/pinot/query/planner/logical/RelToPlanNodeConverterTest.java	Add UUID column type conversion tests and reject UUID arrays.
pinot-query-planner/src/main/java/org/apache/pinot/query/type/TypeFactory.java	Map Pinot UUID to Calcite SqlTypeName.UUID.
pinot-query-planner/src/main/java/org/apache/pinot/query/planner/serde/RexExpressionToProtoExpression.java	Map UUID column type to proto enum.
pinot-query-planner/src/main/java/org/apache/pinot/query/planner/serde/ProtoExpressionToRexExpression.java	Map proto UUID enum back to planner column type.
pinot-query-planner/src/main/java/org/apache/pinot/query/planner/physical/v2/PRelToPlanNodeConverter.java	Convert Calcite UUID to Pinot UUID; reject UUID arrays.
pinot-query-planner/src/main/java/org/apache/pinot/query/planner/logical/RexExpressionUtils.java	Add UUID literal conversion to/from Rex values.
pinot-query-planner/src/main/java/org/apache/pinot/query/planner/logical/RelToPlanNodeConverter.java	Convert Calcite UUID to Pinot UUID; reject UUID arrays.
pinot-query-planner/src/main/java/org/apache/pinot/query/parser/CalciteRexExpressionParser.java	Serialize UUID literals as canonical strings for SQL/parsing paths.
pinot-plugins/pinot-input-format/pinot-avro-base/src/test/java/org/apache/pinot/plugin/inputformat/avro/AvroUtilsTest.java	Test Avro<->Pinot schema mapping for UUID logical type.
pinot-plugins/pinot-input-format/pinot-avro-base/src/test/java/org/apache/pinot/plugin/inputformat/avro/AvroSchemaUtilTest.java	Test Avro schema JSON object generation for UUID fields.
pinot-plugins/pinot-input-format/pinot-avro-base/src/main/java/org/apache/pinot/plugin/inputformat/avro/AvroUtils.java	Enable Avro UUID logical type conversion + UUID schema handling.
pinot-plugins/pinot-input-format/pinot-avro-base/src/main/java/org/apache/pinot/plugin/inputformat/avro/AvroSchemaUtil.java	Map Avro logicalType: uuid to Pinot UUID + emit uuid logical type in Avro schema JSON.
pinot-plugins/pinot-input-format/pinot-avro-base/src/main/java/org/apache/pinot/plugin/inputformat/avro/AvroIngestionSchemaValidator.java	Fix mismatch message to use extracted Pinot type name.
pinot-integration-tests/src/test/java/org/apache/pinot/integration/tests/custom/UuidTypeTest.java	Offline integration coverage for select/filter/group/distinct/order/join with UUID.
pinot-integration-tests/src/test/java/org/apache/pinot/integration/tests/custom/UuidTypeRealtimeTest.java	Realtime integration coverage via subclassed UUID test.
pinot-integration-test-base/src/test/java/org/apache/pinot/integration/tests/ClusterTest.java	Treat UUID like STRING/BYTES when extracting JSON response values in tests.
pinot-core/src/test/java/org/apache/pinot/core/query/selection/SelectionOperatorUtilsTest.java	Verify result formatting distinguishes UUID (canonical) vs BYTES (hex).
pinot-core/src/test/java/org/apache/pinot/core/query/pruner/BloomFilterSegmentPrunerTest.java	Add UUID bloom filter pruning test; allow mocking with arbitrary DataType.
pinot-core/src/test/java/org/apache/pinot/core/query/distinct/table/BytesDistinctTableTest.java	Test UUID vs BYTES formatting in bytes distinct table (with/without ORDER BY).
pinot-core/src/test/java/org/apache/pinot/core/operator/transform/function/CastTransformFunctionTest.java	Add UUID cast tests, invalid literal rejection, and MV-source rejection.
pinot-core/src/main/java/org/apache/pinot/core/query/reduce/GroupByDataTableReducer.java	Treat UUID like BYTES in group key extraction (raw bytes).
pinot-core/src/main/java/org/apache/pinot/core/query/reduce/filter/PredicateRowMatcher.java	Convert UUID row values to bytes before applying predicate evaluator.
pinot-core/src/main/java/org/apache/pinot/core/query/pruner/ValueBasedSegmentPruner.java	Hash bloom filter values using DataType-aware string formatting (UUID vs BYTES).
pinot-core/src/main/java/org/apache/pinot/core/query/distinct/table/BytesDistinctTable.java	Preserve internal ByteArray and format at the end via schema type (UUID vs BYTES).
pinot-core/src/main/java/org/apache/pinot/core/operator/transform/function/InTransformFunction.java	Parse IN-list literals as UUID bytes when main function type is UUID.
pinot-core/src/main/java/org/apache/pinot/core/operator/transform/function/IdentifierTransformFunction.java	Provide UUID string rendering for UUID columns (from underlying bytes).
pinot-core/src/main/java/org/apache/pinot/core/operator/transform/function/CastTransformFunction.java	Add CAST(... AS UUID) support (STRING/BYTES -> UUID) and string rendering.
pinot-core/src/main/java/org/apache/pinot/core/operator/transform/function/BaseTransformFunction.java	Add UUID metadata and UUID->STRING rendering; prevent generic UUID-as-bytes fallback.
pinot-core/src/main/java/org/apache/pinot/core/operator/filter/RawValueInvertedIndexFilterOperator.java	Support raw inverted index filtering for BYTES and UUID literals.
pinot-core/src/main/java/org/apache/pinot/core/operator/filter/predicate/PredicateUtils.java	Add UUID IN-predicate dictionary id set computation.
pinot-core/src/main/java/org/apache/pinot/core/operator/filter/predicate/NotInPredicateEvaluatorFactory.java	Add UUID raw predicate evaluator support (bytes-set with UUID type).
pinot-core/src/main/java/org/apache/pinot/core/operator/filter/predicate/NotEqualsPredicateEvaluatorFactory.java	Add UUID equals/neq evaluator support for dict and raw paths.
pinot-core/src/main/java/org/apache/pinot/core/operator/filter/predicate/InPredicateEvaluatorFactory.java	Add UUID IN evaluator support (bytes-set with UUID type).
pinot-core/src/main/java/org/apache/pinot/core/operator/filter/predicate/EqualsPredicateEvaluatorFactory.java	Add UUID equals evaluator support for dict and raw paths.
pinot-common/src/test/java/org/apache/pinot/common/utils/PinotDataTypeTest.java	Add UUID conversions and type inference tests.
pinot-common/src/test/java/org/apache/pinot/common/utils/DataSchemaTest.java	Add UUID column type coverage (compat, formatting, conversion).
pinot-common/src/test/java/org/apache/pinot/common/response/encoder/JsonResponseEncoderTest.java	Add UUID round-trip encoding/decoding test for result tables.
pinot-common/src/test/java/org/apache/pinot/common/request/context/RequestContextUtilsTest.java	Test filter conversion for UUID cast literals on RHS.
pinot-common/src/test/java/org/apache/pinot/common/function/FunctionUtilsTest.java	Test UUID Java type mappings to Pinot types and Calcite rel types.
pinot-common/src/main/proto/expressions.proto	Add UUID to proto ColumnDataType enum.
pinot-common/src/main/java/org/apache/pinot/common/utils/PinotDataType.java	Add UUID PinotDataType and conversions/toInternal handling.
pinot-common/src/main/java/org/apache/pinot/common/utils/DataSchema.java	Add UUID ColumnDataType, internal/external conversions, formatting and rel type mapping.
pinot-common/src/main/java/org/apache/pinot/common/response/encoder/JsonResponseEncoder.java	Treat UUID like STRING/BYTES when extracting JSON-encoded row values.
pinot-common/src/main/java/org/apache/pinot/common/request/context/RequestContextUtils.java	Add literal-only CAST evaluation on predicate RHS; support UUID cast literals.
pinot-common/src/main/java/org/apache/pinot/common/request/context/predicate/BaseInPredicate.java	Add UUID value parsing/cache for IN predicates.
pinot-common/src/main/java/org/apache/pinot/common/function/scalar/StringFunctions.java	Reuse UuidUtils for UUID bytes conversions.
pinot-common/src/main/java/org/apache/pinot/common/function/FunctionUtils.java	Add UUID Java type mappings and Calcite rel type mapping.

[Copilot]

Pull request overview

Copilot reviewed 85 out of 85 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 97 out of 97 changed files in this pull request and generated 4 comments.